The 24"x 15"x 18" IS the size of a larger rolling suitcase, rolling cooler or (as I have brought in the past) a rolling Toolbox into which I have stuffed 2 "Trading Bags", Binder and Boxed Sets, etc..
Disney has said for years "1 Trading Bag per person" to mean the aforementioned 24"x 15"x 18".
What they
may enforce is the "1 per person" as people, in the past, HAVE dragged in 2 suitcases at a time to the back Trading area.
Also the Table Space restriction
may limit a person to have only 4 Trading Bags on the Table at a time (instead of 1 person taking up 5 spaces or more worth).
Abyssinian28, you know darn well that Disney will let you drag into World Showplace whatever will go thru Security, as in the past. All this "Panic" talk is unproductive.
Let's all grab our "Dancing Brooms", load all our pins onto the "Mine Train" and prepare for a "Pixie Dust" filled ride to the Animation Celebration!!!